Sentences with phrase «sample size variation»

The sample size variation was due to a disparity in subject recruitment between the schools.

Not exact matches

Because there's significant microbiome variation within C - section and vaginal birth groups, a small sample size makes it especially difficult to catch enduring microbiome changes.

As UPC Prof at ICFO Juan P. Torres states, «any slight refractive index change introduced by an impurity in the sample is translated into a phase difference and thus an intensity variation in the pattern, showing the contours and therefore size of the irregularity.»

A Commentary article in the same issue of The Lancet Diabetes and Endocrinology by Harvard Professor Matthew W. Gillman notes that the study had a large sample size, reasonably precise information about the timing of the famine, geographical variation in the same country, and clinical outcomes — a combination of strengths missing in other famine studies.

Sample sizes do not permit rigorous intragroup comparisons, but Neandertal molar tissue proportions evince less variation than the modern human sSample sizes do not permit rigorous intragroup comparisons, but Neandertal molar tissue proportions evince less variation than the modern human samplesample.

This aspect must be evaluated in association with the pronounced body - size variation within the sample, which implies marked differences between age ranges and a considerable degree of sexual dimorphism in Au.

Garamszegi, L. Z. & Møller, A. P. Effects of sample size and intraspecific variation in phylogenetic comparative studies: a meta - analytic review.

Using large - scale empirical and simulated data sets, we found that the sample sizes used in the HapMap project are sufficient to capture common variation, but that performance declines substantially for variants with minor allele frequencies of < 5 %.

(Our sample size allowed us to identify how much variation in achievement was associated with textbooks, but not necessarily to evaluate the effectiveness of each textbook individually.

«The beauty of a meta - analysis is that you can look at all of the existing studies and calculate the strength of the relationship between one variable and another, taking into account variations in sample size, region of a country, quality of the study, and other factors,» Hill says.

Among median - size schools in North Carolina, roughly half of the variance between schools in value - added in 4th grade math and reading was due to sampling variation and other one - time factors.

We sampled districts to achieve variation in size and demographic diversity.

As with the cases discussed above, the differences could come from variations in teachers» true value - added across student groups or from measurement error enhanced by the small sample size.

Out of that pool of variation, which is getting to be a significant sample size, comes this one video that manages to land on a simple concept that plays to the strengths of the film medium — namely that it is visual.

However, the small sample size, lack of randomization, wide variation in children served, and the lack of objectively assessed changes in child behavior limit the reported results.

This variation, along with the sample size for each model, will be taken into account in the final analysis.

Limitations include lack of a non-maltreated or child welfare services involved comparison group, possible sample collection time variation, and small sample size.

With regard to the sample size required for valid application of this modeling approach, we are hesitant to speak of sufficient sample sizes, since a large number of observations with little score variation over time (as in our second empirical application) does not necessarily provide richer information than a smaller sample with more fluctuations.

The distribution of effect sizes should be shaped as a funnel if no publication bias is present, since the more numerous studies with small sample sizes are expected to show a larger variation in the magnitude of effect sizes than the less numerous studies with large effect sizes.

In our meta - analytic model, three forms of variance were taken into account: random sampling variation of observed effect sizes (level 1), variance within studies (level 2), and variance between studies (level 3)(Cheung 2014; Hox 2002; Van den Noortgate et al. 2013, 2014).